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BOLD IDEAS

winning cities across the competitions

• STOCKHOLM : 2014 WINNER •

Biochar: Engaging Citizens in the Fight Against Climate Change

The Problem

Climate change is one of the greatest threats of our era. The City of Stockholm aims to become a fossil free city by 2040 and citizens want to help: eight in ten residents say they want to be more active in the fight against climate change. Still, the City lacks solutions that engage residents or provide them with a way to directly contribute to the City’s goal.
 

The Innovation

Stockholm’s Biochar Project aims to reduce carbon emissions by enabling citizens to be part of carbon sequestration. Residents will provide plant waste to the City, which will produce biochar – a charcoal-like product that can sequester carbon in soil for thousands of years. Biochar, when placed in plant beds, improves soil structure, encourages plant growth, and helps to purify storm water run-off. Additionally, a by-product of the biochar production process is pyrolysis gas, which will be used to generate energy for the City’s district heating system. While there are examples of biochar use across Europe, Stockholm will implement the first large-scale collaboration between local authorities and citizens in the generation of the product.
 

The Impact

Stockholm’s first physical biochar plant launched in March 2017. The City anticipates the plant will produce 7,000 tons of biochar by 2020, which will sequester 25,200 tons of CO2 (the equivalent of taking 3,500 cars off the road) and produce a corresponding 25,200 megawatt hours of energy. Click here to learn more about the biochar life cycle.
 
The City has already received nearly 100 requests from cities and organizations who are interested in replicating the program. As a result, the team has published a replication manual and checklist for reference.